Elkaseh A A O, Perold W J, Srinivasu V V
Department of Electrical and Electronic Engineering, Stellenbosch University, Stellenbosch 7602, South Africa.
J Nanosci Nanotechnol. 2010 Oct;10(10):6510-3. doi: 10.1166/jnn.2010.2539.
The critical current (Ic) of YBa2Cu3O7-x (YBCO) AFM plough micro-constrictions is measured as a function of temperature, width and the magnetic flux density (B), which was applied perpendicular to the YBCO ab-plane and surface of the bridges. C-axis oriented thin films of YBa2Cu3O7-x were deposited on MgO substrates using an inverted cylindrical magnetron (ICM) sputtering technique. The films were then patterned into 8-10 micron size strips, using standard photolithography and dry etching processes. Micro-bridges with widths between 1.9 microm to 4.1 microm were fabricated by using atomic force microscope (AFM) nanolithography techniques. Critical current versus temperature data shows a straight-line behavior, which is typical of constriction type Josephson junctions. The Ic versus B characteristics exhibited a modulation, and a suppression of the critical current of up to 84%. It was also found that the critical current increases with increasing constriction width.
测量了YBa2Cu3O7-x（YBCO）反铁磁犁形微缩结构的临界电流（Ic）随温度、宽度和磁通密度（B）的变化关系，磁通密度垂直于YBCO的ab平面和桥的表面施加。采用倒置圆柱磁控管（ICM）溅射技术在MgO衬底上沉积了c轴取向的YBa2Cu3O7-x薄膜。然后使用标准光刻和干法蚀刻工艺将薄膜图案化为8 - 10微米尺寸的条带。通过原子力显微镜（AFM）纳米光刻技术制备了宽度在1.9微米至4.1微米之间的微桥。临界电流与温度的数据呈现出直线行为，这是收缩型约瑟夫森结的典型特征。Ic与B的特性表现出调制，临界电流抑制高达84%。还发现临界电流随收缩宽度的增加而增加。
